Molecular Genetics (i FTE). The primary function of this core is to purchase, test and distributed DNA, antibody and other assay reagents shared across all CDP research groups. Given the small materials and supplies budgets in most individual projects, the $100,000 budget of the Molecular Genetics core is absolutely essential to all experimental work in CDP. Over the past four years we have found that joint purchase of reagents permits us to achieve economies of scale and reduce significantly total costs. In addition, the knowledge that we are all using reagents from a common pool makes it much easier to share protocols and troubleshoot problems. The core's research scientist, Sean Milton, has worked in CDP since its inception and was previously responsible for building MIT's BioMicro Center, which provides DNA arraying and expresson profiling services. Sean's mission is to develop detailed protocols for protein and gene assays that he himself develops, or that are developed by postdocs and students in CDP. Sean then distributes these protocols within the group and to outside parties, and serves as a source of expertise for people applying methods for the first time. Sean's role is among the most important in CDP since he plays the single largest role in knowledge retention and propagation. Sean also manages the core gene and protein resources of CDP and negotiates volume purchases of key reagents. Finally, Sean participates actively in teaching graduate students and postdoctoral fellows in the summer course; he is also active in CDP retreats and conferences.